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BENTHAM AND HOOKER’S SYSTEM OF ANGIOSPERM CLASSIFICATION. Submitted by: Dr. Geetanjali, Assistant Professor, Botany Department, Government College for Girls, Sector-11,Chandigarh. INTRODUCTION.
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BENTHAM AND HOOKER’S SYSTEM OF ANGIOSPERM CLASSIFICATION Submitted by: Dr. Geetanjali, Assistant Professor, Botany Department, Government College for Girls, Sector-11,Chandigarh.
INTRODUCTION • Classification denotes the arrangement of a single plant or group of plants an distinct category following a system of nomenclature, and in accordance with a particular and well established plan. • Some of the earlier systems of classification of angiosperms were artificial systems, since they used only certain superficial characteristics as the basis. • With more and more detailed study on the morphological, physiological and reproductive aspects of angiosperms, the artificial systems of classifications were replaced by the naturalsystems of classification.
George Bentham and Joseph Dalton Hooker - Two English taxonomists who were closely associated with the Royal Botanical Garden at Kew, England have given a detailed classification of plant kingdom, particularly the angiosperms. • They gave an outstanding system of classification of phanerogams in their Genera Plantarum which was published in three volumes between the years 1862 to 1883. It is a natural system of classification. • They described 97,205 species of flowering plants grouped into 202 orders (now recognised as families). • The system has the advantage of being the first great natural system of classification, which is very easy to follow.
George Bentham 1800-1884 Joseph Dalton Hooker 1817-1911
SUB-CLASS - POLYPETALAE petals separate Series THALAMIFLORAE DISCIFLORAE CALYCIFLORAE Orders Orders Orders Ranales Geraniales Rosales Parietales Olacales Myrtales Polygalineae Celastrales Passiflorales Caryophyllineae Sapindales Ficoidales Guttiferales Umbellales Malvales
THALAMIFLORAE Many stamens in the androecium. Flower is hypogynous Orders Ranales Parietales Polygalineae Caryophyllineae Guttiferales Malvales Families Families Families Families Families Families Malvaceae Pittosporaceae Elatinaceae Ranunculaceae Sarraceniaceae Frankeniaceae Sterculiaceae Hypericaceae Caryophyllaceae Dilleniaceae Tremandraceae Papaveraceae Tiliaceae Guttiferae Portulacaceae Polygalaceae Calycanthaceae Cruciferae Theaceae Tamaricaceae Magnoliaceae Capparaceae Dipterocarpaceae Annonaceae Resedaceae Sarcolaenaceae Menispermaceae Cistaceae Berberidaceae Violaceae Canellaceae Nymphaceae Bixaceae.
DISCIFLORAE Hypogynous flowers with a cushion-like disc around or below the ovary Orders Geraniales Olacales Celastrales Sapindales Families Families Families Families Olacaceae Linaceae Celastraceae Sapindaceae Stackhousiaceae Aquifoliaceae Meliosmaceae Humiriaceae Rhamnaceae Anacardiaceae Malpighiaceae Coriariaceae Vitaceae Zygophyllaceae Moringaceae Geraniaceae Rutaceae Simaroubaceae Ochnaceae Burseraceae Meliaceae Dichapetalaceae
CALYCIFLORAE • Flowers epigynous or perigynous • Thalamus is in the form of a cup Orders Rosales Myrtales Passiflorales Ficoidales Umbellales Families Families Families Families Families Umbelliferae Rhizophoraceae Cactaceae Connaraceae Loasaceae Araliaceae Aizoaceae Turneraceae Leguminosae Combretaceae Cornaceae Myrtaceae Rosaceae Passifloraceae Melastomataceae Saxifragaceae Cucurbitaceae Lythraceae Begoniaceae Crassulaceae Onagraceae Datiscaceae Droseraceae Hamamelidaceae Bruniaceae Haloragaceae
SUB-CLASS - GAMOPETALAE petals fused Series INFERAE HETEROMERAE BICARPELLATAE Orders Orders Orders Rubiales Ericales Gentianales Asterales Primulales Polemoniales Campanulales Ebenales Personiales Lamiales
INFERAE Flowers with inferior ovary Orders Rubiales Asterales Campanulales Families Families Families Valerianaceae Caprifoliaceae Stylidaceae Dipsacaceae Goodeniaceae Rubiaceae Calyceraceae Campanulaceae Compositae
HETEROMERAE • Flowers with superior ovary • Number of carpels - more than two Orders Ericales Primulales Ebenales Families Families Families Ericaceae Plumbaginaceae Sapotaceae Clethraceae Primulaceae Ebenaceae Epacridaceae Myrsinaceae Styracaceae Diapensiaceae Lennoceae
BICARPELLATAE • Ovary superior, with 2 carpels Orders Gentianales Personiales Lamiales Polemoniales Families Families Families Families Oleaceae Polemoniaceae Scrophulariaceae Myoporaceae Salvadoraceae Hydrophyllaceae Globulariaceae Verbenaceae Apocynaceae Boraginaceae Lentibulariaceae Labiatae Asclepiadaceae Convolvulaceae Gesneriaceae Plantaginaceae Loganiaceae Bignoniaceae Solanaceae Pedaliaceae Gentianaceae Acanthaceae
Loranthaceae Nyctaginaceae Batidaceae Santalaceae Amaranthaceae Polygonaceae Balanophoraceae Phytolaccaceae Chenopodiaceae MONOCHLAMYDEAE only 1 kind of perianth Series Curvembryae Multiovulate Aquaticae Multiovulate Terrestris Microembryae Daphnales Achlamydo -sporae Unisexuales Ordines Anomali Families Families Families Families Families Families Families Families Podostemaceae Nepenthaceae Piperaceae Lauraceae Euphorbiaceae Salicaceae Cyinaceae Chloranthaceae Proteaceae Balanopaceae Empetraceae Ceratophyllaceae Myristicaceae Myristicaceae Thymelaeaceae Urticaceae Monimiaceae Penaeaceae Ficoidales Ficoidales Platanaceae Lacisternaceae Elaegnaceae Leitneriaceae Juglandaceae Myricaceae ficoidales Casuarinaceae Betulaceae
CLASS-MONOCOTYLEDONAE 1 cotyledon, flowers trimerous Series Microspermae Epigynae Coronarieae Calycinae Nudiflorae Apocarpae Glumaceae Families Families Families Families Families Families Families Eriocaulaceae Roxburghiceae Flagellariaceae Triuridaceae Hydrocharitaceae Scitamineae Pandanaceae Centrolepidaceae Juncaceae Alismataceae Cyclanthaceae Burmanniaceae Liliaceae Bromeliaceae Restionaceae Palmae Najadaceae Typhaceae Pontederiaceae Orchidaceae Haemodoraceae Cyperaceae Araceae Philydraceae Iridaceae Gramineae Lemnaceae Xyridaceae Amaryllidaceae Mayacaceae Taccaceae Commelinaceae Dioscoreaceae Rapateaceae
RANUNCULACEAE Delphinium amplibracteatum Ranunculus laetus
PAPAVERACEAE Argemone mexicana
RUTACEAE Citrus limon Citrus aurantifolia Murraya paniculata Murraya koenigii
LEGUMINOSAE Pisum sativum Lathyrus odoratus
UMBELLIFERAE Coriandrum sativum -
ASCLEPIADACEAE Asclepias quinquedentata Calotropis
SOLANACEAE Nicotiana glauca Solanum nigrum
LAMIALES Ocimun
Euphorbia pulcherime EUPHORBIACEAE Euphorbia hirta
GLUMACEAE Triticum aestivum Oryza sativa
DRAWBACKS • Gymnosperms were placed between Dicots and Monocots. • Many important floral characters were neglected. • It is not a phylogenetic scheme. • Some of the closely related families have been separated and placed under different cohotrs and a number of unrelated families put together. • Some advanced families like Orchidaceae have been regarded as primitive by placing in the beginning.